Chronic abdominal wall pain

Chronic abdominal pain is a problem that can occur after abdominal wall surgery (e.g. surgery for an umbilical hernia or incisional hernia) or surgery in the abdominal cavity, but can also occur without prior surgery. The cause of the pain can either be caused by an implanted hernia mesh or by the entrapment or irritation of abdominal wall nerves, the so-called ACNES (Anterior Cutaneous Nerve Entrapment Syndrome). The entrapment in ACNES usually occurs when the nerves enter the box of the straight abdominal muscles.

The pain worsens with physical exertion, is often described as stabbing, burning or electrifying and severely restricts the quality of life of affected patients. There is often a clear trigger point (pain trigger) whose touch can trigger the pain. The pain usually radiates along the nerves to the lateral trunk wall and the midline.

Unfortunately, abdominal wall pain is often not optimally diagnosed and treated. As a result, many patients often spend months or years seeing different doctors without any improvement in their symptoms. In some cases, those affected are also assumed to have a psychosomatic illness, which leads to despair and hopelessness. 

In addition to the pain, many patients also describe pronounced vegetative symptoms. These include, for example, digestive disorders (flatulence, intestinal cramps), disorders of the cardiovascular system (palpitations, fluctuations in blood pressure) and sweating.

As a rule, the diagnosis is made by thoroughly questioning the patient, inspecting records (e.g. old operation reports) and carrying out a thorough physical examination. The pain points are located and marked with a pen using «mapping» and documented with photographs. If the patient’s medical history and examination results are suitable, the «trigger points» are usually infiltrated with a local anesthetic during the first consultation. The pain can usually be eliminated immediately.

Depending on how the pain responds to the infiltration, the treatment is then repeated, interventional pain therapy (e.g. with cryoablation or radiofrequency ablation) or surgical treatment, for example by surgically removing the affected nerve.

In a few cases CPIP can occur due to ingrowth of the nerves in scar tissue of the sutures or the mesh. Besides surgical expertise, diagnostic and treatment of CPIP demands a careful physical examination, detailed medical history taking, and the use of imaging modalities (MRI). Also, a pain mapping should be performed to get a clear understanding of the problem and the affected nerves. In some cases, repeated infiltration of the groin with a long-acting local anesthetic agent can induce continuous pain reduction («desensibilization»). In some cases a percutaneous nerve ablation or a surgical neurectomy (with or without mesh removal) is necessary to treat CPIP successfully. The overall success rate for treating CPIP is 75-80%.